An apple plant has two dominant alleles for red apples, rr. if it is crossed with another plant that has recessive genes for green apples, rr, which percentage of the offspring will have red apples, assuming random chromosome segregation? a) 25% b) 50% c) 75% d) 100%

Option D

Explanation:

Whenever there is cross between a Homozygous dominant  and a  Homozygous recessive parent, the offspring’s produced will be Heterozygous dominant

Here the  

Homozygous dominant red apple is represented by RR

Homozygous recessive apple is represented by rr

The cross between the two is represented by the punnet square as given below –  

RR

rRrRr

rRrRr

Thus all the offsprings possess heterozygous dominant allele.  

measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.